Vitamin D Status and Resting Metabolic Rate May Modify through Expression of Vitamin D Receptor and Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Gene in Overweight and Obese Adults

Abstract

Background: Resting metabolic rate (RMR) used to prognosticate and measure the amount of energy required. Vitamin D is known as a new predictor of RMR. The aim of this study is to investigate the relationship between vitamin D effects on RMR in connection with the vitamin D receptor (VDR) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) gene expression. Methods: We enrolled 298 overweight and obese adults in this cross-sectional study. Body mass index (BMI), fat mass, fat-free mass, insulin level, visceral fat, and vitamin D status were assessed. RMR was measured by means of indirect calorimetry. The real-time polymerase chain reaction using specific primer pairs for VDR and PGC-1α was performed. Results: There were significant differences in terms of fat free mass, fat percentage, insulin levels, RMR/kg body weight, and RMR/BMI, VDR, and PGC-1α among participants were categorized based on the vitamin D status. But after using general linear model for adjusting, all significant results missed their effectiveness except RMR/kg body weight and VDR. Linear regression analysis used to show the mediatory role of VDR and PGC-1α on the RMR/kg body weight and vitamin D status relationship. Our results showed that VDR had a mediatory effect on the relationship between RMR/kg body weight and vitamin D status (β = 0.38, 95% CI –0.48 to 1.60; β = –1.24, 95% CI –5.36 to 1.70). However, PGC-1α did not affect the relationship between RMR/kg body weight and vitamin D status (β = 0.50, 95% CI = –0.02 to 3.42; β = 0.59, 95% CI 0.14–3.90). Conclusion: Our study showed the mediatory effect of VDR gene expression in the association of 25(OH)₂D plasma levels and resting metabolic rate among obese individuals.

Lack of a relationship between vitamin D status and resting metabolic rate in Iranian adults

“…The driver for our study was observations that vitamin D status had a direct association with RMR in Australian adults after accounting for several confounding factors (Calton et al, 2016). This has also been observed in a large number of Iranian overweight and obese where a significant positive correlation between vitamin D status and RMR/kg was obtained (Sajjadi et al, 2018). However, a short-term (7 days) randomized controlled trial of vitamin D supplementation (2000 IU), which was conducted on 10 young men, did not show any effect of vitamin D on energy expenditure (Boon et al, 2006).…”

“…Moreover, higher prevalent vitamin D status was associated with greater postprandial thermogenesis and insulin sensitivity (Pathak et al, 2017). A study published in Iran also reported the role of VDR in the regulation of RMR (Sajjadi, Mirzaei, Khorrami-Nezhad, Maghbooli, & Keshavarz, 2018). Therefore, this study aimed to determine the association of vitamin D status with RMR independent of body composition in Tehranese adults.…”

Adipokines, Myokines, and Cardiokines: The Role of Nutritional Interventions

“…In diabetic animal models, vitamin D increases irisin expression [160]. In overweight and obese patients, depletion of vitamin D is associated with worsened inflammatory state in obese [161], whereas vitamin D stimulus upregulated PGC-1α expression and consequently irisin secretion [162] Moreover, Safarpour et al have demonstrated that in obese and diabetic subjects vitamin D supplementation counteracts impaired insulin signaling and increased irisin signaling pathway [163]. Then, the relationship between irisin and vitamin D should be further investigated.…”

Daily intake of yogurt drink fortified either with vitamin D alone or in combination with added calcium causes a thyroid-independent increase of resting metabolic rate in adults with type 2 diabetes: a randomized, double-blind, clinical trial

“…Notwithstanding, this effect may, at least in part, be due to dietary calcium-induced increased D r a f t fecal fat excretion (Christensen et al 2009;Kjølbaek and Lorenzen 2017). On the other hand, the effect of vitamin D on RMR and body weight may be mediated through VDR (Sajjadi et al 2018). Adequate intake of dairy calcium and vitamin D may help weight loss (Shahar et al 2010) probably through, at least in part, increased EE.…”